Car tire rotation is only a viable option if there is more than a sixteenth-of-an-inch of tread left on your tires. You cannot ignore the treadware bars that will show up at that point. If, on the other hand, your car tires have plenty of tread left on them, then using standard rotation is certainly preferable to buying new tires every time you have to rotate them. As long as there’s more than the mandated minimum on the tire, just rotate the tires and have them rebalanced and you are on your way. It might be a good idea, too, at this time, to have an alignment done, just to make sure that your car is handling correctly.
For more info, see How Often Should You Replace Tires